Fish


 * Long Island Fish Inventory, 2012 **

Image 1: Captured Fish Species

 In the past, efforts to restore the biotic integrity of water resources have been directed primarily toward improving the chemical and physical water quality of point source effluents. By analyzing the biodiversity of fish species present within the stream specific parameters such as habitat alteration, flow regime modification, and changes in the trophic base of the stream biota are no longer overlooked. Advantages of using fish as biotic indicators include longer life histories providing an assessment of the long-term health of the stream. Fish are also sensitivite to direct stresses such as point source and non-point source pollution, sedimentation, habitat loss, and riparian zone. Fish also provide an integrative view of the entire watershed allowing for evaluations of degradation relating to both their economic and aesthetic values, (Karr 1987). Biotic integrity monitoring in accordance with bioassay testing allows for an accurate integrated system of water quality management.

Image 2: Forty-five meter reach sampled at Long Island Creek

Data was collected from Long Island Creek upstream from Jett Road on June 21, 2012 using standard stream electrofish-shocking methods, [|Journal of Wildlife Management] .This site is a post restoration site where severe bank erosion, channeling, and limited vegetation previously dominated the landscape.With the aid of rip-raps and vegetative buffers lining the bank and surrounding area this stretch of stream has become home to a Blue Heron, several fish species, countless invertebrates, and other wildlife. Seventy-five meters in length of stream were sampled: this reach was less than that recommended in the Standard Operating Procedures developed by the WRD, thus the overall IBI score and narrative ranking should be considered illustrative rather than definitive, [|Sampling Protocols and SOP]

Image 3: //Semotilus thoreauianus//, Dixie Chub (left) and //Lepomis auritus//, Redbreast Sunfish (right)

 As seen in Table 1 below there were eleven species of fish collected with a total of 81 fish species captured. Total abundance of fish species was observed to of decreased from the previous year’s study by twenty-four individuals, inferring this is a low number of species expected. Accordingly, the most abundant species found was the Alabama Hogsucker followed by the Redbreast sunfish, see chart 2. Neither one of these species is considered intolerant indicating that the fish community currently present within the stream tolerate a large range of environmental /stream conditions, hence not a clear indicator of stream health. There were also several insectivore species observed such as the Southern studfish, Redbreast sunfish, Bluegill sunfish, and Alabama Hogsucker. Insectivore species of fish can be reflective of the invertebrate population within the stream: invertebrates are the primary source of sustainability for insectivore species.



The Index of Biotic Integrity, (IBI), was developed to assess the health of aquatic communities based on the functional and compositional attributes of the fish population. IBI assesses the biotic integrity of a stream by assigning scores to metrics, such as number of native fish species found and the number of specific species that occupy particular niches. Metric scores are based on the scoring criteria developed by the Georgia Department of Natural Resources Wildlife Resources Division (WRD) for the Chattahoochee Basin and Piedmont ecoregion. The metrics in Table 2 are scored based on a 1, 3, 5 scale with 1 as the lowest score and 5 the best. Although higher than the previous year’s IBI results, a total score of 30 was obtained inferring that the overall health of the stream is still poor, [|IBI Metrics]

Image 4: Healthy Stream. Happy Fish.